One type of known metal beverage container has a screw-on closure cap. With this type of metal container, an open end of the container may be opened and resealed using the screw-on closure cap. These containers generally resemble screw top bottles having a necked-in upper portion terminating at a threaded open end. Another type of known metal beverage container includes a curled rim or lip at the open end. Each of these types of containers may be formed using an impact extrusion process. Impact extrusion is a process utilized to make metal containers and other articles with unique shapes. The containers are typically made from a softened metal slug comprised of steel, magnesium, copper, aluminum, tin, and lead and other alloys. The container is formed inside a confining die from a cold slug which is contacted by a punch. The force from the punch deforms the metal slug around an outer diameter of the punch and the inner diameter of the confining die. After the initial shape is formed, the container is removed from the punch with a counter-punch ejector, and other necking and shaping tools are used to form the container to a preferred shape. Presently, the impact extrusion containers are mechanically finished by separate forming devices with a thread and/or a curled rim or lip. The threaded only metal containers can have a sharp edge which is unacceptable for drinking. The metal containers with only a curled rim or lip are not resealable.
Recently, lug-type resealable closure systems have been introduced into the metal beverage container market. These closure systems include a set of elongated outwardly extending lugs formed (e.g., by an embossing process) about the container at an upper neck portion. These lugs cooperate with a second set of inwardly extending lug members formed in a curled rim of a cap. When the cap is attached to the upper neck portion, the cooperating lug members draw the cap against a curled seal rim or lip mechanically formed on the container. Although the lug-type closure systems overcome some of the drawbacks of the threaded closures because the relatively expensive operation of threading the wall of the container body is avoided, the metal containers having these lug-type closures together with the curled seal rim or lip cannot be reliably impact extruded which can increase the cost of manufacturing.